"Whether...hazards turn into a natural disaster has been summarized by the following simple Pressure and Release (PAR) Model: Disaster Risk = Hazard + Vulnerability. The likelihood of hazards leading to disasters is thus primarily dependant on an area or people's level of vulnerability. Many issues can increase vulnerability but these tend to depend upon: (1) root causes: e.g. limited access to resources or poor political or economic systems (2) dynamic pressures: e.g. lack of training, skills, investment, local institutions (3) macro-forces: e.g. rapid population growth or urbanization, poor planning, deforestation, decline in soil productivity Together these issues can result in vulnerable conditions (e.g. fragile physical environments or local economies, or lack of preparedness to disaster) which when combined with a hazard can lead to disaster. The level of vulnerability, and thus the likelihood of a hazard developing into a disaster, is therefore in many cases in our control". (WWF, Natural Security, 1008, 17; cites Blaikie, At Risk, 1994)